Introduction and technology update:

Since the last instalment Seoul Semiconductors has produced a more powerful LED the P7, it produces 900 Lumens at 11.8W. Cree has increased the efficiency of the XLamp XR-E making it slightly more efficient then the Seoul P4. For this design, for cost, availability and ease of use, I have chosen to use the Seoul P4 LED.

The keep the design as cheap and simple as possible I have chosen to power the LED by standard AA rechargeable batteries, these can be recharged in an off the shelf charger.

The design aim is to give a minimum of 5 hours /100 Lumens on main, and 24 hours / 20 Lumens on pilot. Thus the main beam should be slightly brighter than a Nova 3.